This invention relates to a driving circuit for a gas discharge panel having control cells.
In one type of gas discharge panel disclosed in U.S. patent application Ser. No. 555,139, now U.S. Pat. No. 3,976,971, filed by Tsunekiyo Iwakawa and Akira Yano, assignors to the present assignee, a set of first electrodes are disposed opposite to a set of second electrodes and to third electrodes which are in one-to-one correspondence with the first electrodes. Gas discharge spaces or cells for developing desired displays (herein named display cells) are defined between each of the second electrodes and at least one of the first electrodes. Gas discharge spaces or cells for performing the control function of selectively supplying an electric voltage to the first electrodes (herein called control cells) are formed between the first electrodes and the corresponding third electrodes.
To make the control cells carry out the control function, a driving circuit for a gas discharge panel of the type described comprises a circuit for selecting the control cells, one at a time. The selecting circuit in turn comprises, a switching element, such as a transistor, connected to each third electrode. Switching or control signals are selectively supplied to the switching elements to render the switching element connected to only one of the third electrodes off or nonconductive at a time while maintaining other switching elements on, or conductive.
When there are a large number of first electrodes, a similarly large number of switching elements have invariably been used, consequently giving rise to an expensive driving circuit. When coded signals are used to select the control cells, it has been necessary to resort to a decoder to derive the switching signals from the coded signals.